Im after a little advice with my listing details. I have a property in Cornwall, England currently listed as accommodating 10 guests. I do however have 2 new Z beds which can be placed into 2 of the bedrooms to allow another person to stay in each. The Z beds are fine for children and teenagers but probably not brilliant for fully grown men or larger people. Is it fair for me to list the property as accommodating 12 guests and then make comment about the Z beds in the listing details or better to leave as accommodating 10 guests and then explain Z bed option on the listing details. Obviously the ability to accommodate 12 guests rather than 10 could open up additional potential bookings but I don’t want to mislead or disappoint guests. What do you think?
10 guests and let them know if they need the Z beds you have them. I wouldn’t put it in the listing I would just use them if I need them. As it is you’ll probably get people sneaking in guests or asking if they can bring more even if your limit is 10.
I would put 12 if you want to allow 12 to stay. In the listing, you have to specify what type of bed is in each bedroom, so I would choose “air mattress.” (I think that’s one of the checkboxes that you can pick from.) Like in bedroom one, you choose one bed and one air mattress, etc. And then in the body of your listings, just explain what the beds are.
You can always start by indicating 12 and revise it to 10 later if you have problems.
That’s what I did. My unit can sleep 8. I ran into some of the issues described by @KKC.
I now advertise it for 5 occupants. However I continue to include the 2 couches and 1 Air bed in the beds available section because they are sleeping choices in addition to the 1-queen, 1-double & 1 twin beds in the condo.
Note that on Airbnb the maximum number of guests that can be booked and “extra guest fee” charged is limited by your stated maximum occupancy.
Meaning if your maximum # guests = 10,
Person A wants to bring 11,
you must adjust your maximum # of guests before they can book,
then after they book, change it back to 10 for future bookings.
I would think really hard about packing them in like sardines …
So would I. I’ve sometimes wondered what sort of groups travel in a pack of twelve. I can just about understand a group of ten or fewer - parents, kids, a couple of grandparents - I see that as being a family but twelve I can only imagine as a group of partiers,
I’ve been pondering that comment.
More Heads in beds = greater revenue potential but I’m not sure if I want it!
Too many people in too small of a space means increased wear & tear on the unit, super bargain shoppers & increased work for the owner. It is a trade off to limit # of guests vs. potential revenue.
I can’t tell you where the limit is but it is wise to consider how many heads in beds there should be.
One answer, not necessarily the answer, is to not venture beyond what the host, the property and the furnishings can handle. I’ve seen listings with beds crammed into every available space and I can’t see how the laundry and linen damage costs could be handled by the low per-person price. It’s okay being able to sleep x number of people but can they all sit to watch TV or to dine? Are there enough bathrooms to cope? Can the plumbing cope? But most importantly to me, can the host cope? I know I wouldn’t be able to!
My Costa Rica trip had eight but the max occupancy of the house was 14 and I invited 14. If everyone had gone, yes, we would have been partiers, just as we were with a group of 8. Of course a bunch of middle aged women partying isn’t the same as some groups.
That’s what you think 
Interesting coincidence—-a good friend was just sharing her frustration finding a place on Airbnb or VRBO to accomodate 14 women (ages 52-84) going on a kayaking trip. They paddled all day. Ate dinners out and were exhausted & in bed by 9 pm. Hosts kept expressing concerns overs parties. Yep apparently we middle-aged and geriatric women have quite the party-hardy reputation. 
Have you hosted previously?
Either way, I think you might need to experiment to see what best works, but if you’re a new host I’d list at 10 so you build good reviews. Ten people booking ten good beds, where bathrooms aren’t over-crowded and common areas have enough seating, might give better reviews than maximizing revenue by adding head count.
There is no 1 size fits all … but my take on this:
Situation A:
I went on a family trip - a get together of roughly up to 14 invited family members. While the house accommodated all invitees and probably charged a hefty charge after x persons for each, quite a few had ringy dingy whatever camping beds - I was glad I got assigned a room and not the retrofitted communal dorm in the downstairs entertainment room.
If I would have been the person booking the space and got one of those beds, my aching back would probably tell my fingers what to write in the review …lucky for the hosts that offer such a space, the one that books, gets first pick and rarely picks the worst sleeping spot.
And, well, we might never had that family get together if the option would have not been available.
Situation B:
We are offering a 3 BR condo at the beach with a limit of 6 guests. One neighbor is packing them in with accepting 8 guests with 9 beds (but we have seen 9 or 10 as well) … with 2 rooms having Queen size beds with a pullout bed underneath in a 12m2/130f2 room (basically there is no space to even get to the bed when the bed is pulled out) and sofa beds in the living room for those that don’t fit in the rooms …
Is that comfy? Not really, but all the guests seem happy and don’t seem to mind that there isn’t even a table for 8 … Are we going to copy that example … nooooo way! We host because we like too, he hosts to pay bills.
Interesting—earlier today I noticed a 1BR 1 BA condo at the beach slightly larger than mine has very little furniture except a double & a queen bed in the BR and two sofa sleepers in the living area. They advertise sleeping 8! Their guests have given it acceptable reviews. With the sofa beds open there can’t be any floor space.
They charge 2x my nightly rate. I’m not interested in following their example although it offers higher earnings.
Also I think one of the neighbors would have a meltdown if 8 people were in my tiny condo beside hers and making noise.
Thanks for all the comments - great to get a range of views. On balance I think i am going to stick with accommodating 10 guests in the listing and just reference the Z beds in the text body as a flexible option. Thanks again. D